Multiple temperature refrigerating system



Jan. 30, 1951 J. c. JENKINS MULTIPLE TEIPERATURE REFRIGERATING SYSTEM Filed llay 19, 1928 C76/ 0 Jaw m .nfa Q Patented Jan. so. 1951 2,539,908

John Glenkins, Minneapolis, Minn assignor to Seeger Refrigerator Company, St. Paul, Minn.

Application May 19, 1948, Serial No. 27,860

7 Claims.

My invention relates to an improvement in refrigerating system wherein it is desired to provide a refrigerating apparatus of the multiple temperature type. L

The object of the presentinvention resides in the provision of a refrigerator having compartments to be maintained at difierenttemperatures and to provide an efficient system for supplying refrigerant to cool the diiferent compartments. A separate coil is provided for each compartment and the coils are connected in such a manner as to cause the system to operate economically.

" A feature of the present invention lies in the provision of a refrigerator system having two evaporator coils which are supplied with refrigerant through twin capillary tubes connected to a common liquid line. The length of capillary used for each coil is calculated to produce the desired restriction and consequently the proper feed.

A feature of the present invention lies in the provision of a pair of capillary tubes fed from a common liquidline to deliver refrigerant-to a pair of evaporator coils. A relatively higher suction pressure is maintained in the high temperature evaporator coil by use of a pressure differential valve located at the outlet of the high temperature evaporator coil. The pressure differein tial valve is connected to the low temperature coil at a point intermediate the ends thereof. As a result the feed to the colder evaporator coil is increased at this point mid-way between the ends of the colder coil.

A feature of the present invention lies in the a refrigerant system embodying the features of my invention.

The refrigerant system may be used on a two temperature refrigerator of any desired typ the $3.: in the construction of the refrigerator de- The system A includes a motor compressor unit It which is provided with a refrigerant inlet H and a refrigerant outlet l2. The outlet I2 is connected to the condenser l3 in which the gaseous refrigerant is liquified. The condenser i3 is connected by a liquid line I to a pair of capillary tubes l5 and I6. Thus the liquid refrigerant is allowed to flow through the two capillary tubes 15 and it which are of proper length to produce the desired feed into each of the evaporator coils.

An evaporator coil I1 is connected to the capillary. tube l5 and a second evaporator coil [9 is connected to the capillary tube IS. The coil [1 is designed to comprise the low temperature coil and is held at proper temperature to produce a temperature of approximately zero degree within the low temperature compartment 20. The coil I9 is located within a relatively high temperature compartment 2| and is designed to hold the temperature within this compartment at approximately degrees.

The coil I9 is provided with a pressure differential valve 22 at its outlet end. The pressure within the coil I9 is held relatively high and may be for example thirty pounds per square inch. The differential valve 22 allows a greater expansion of the refrigerant and the coil I1 is maintained at a relatively low pressure such as for example a suction pressure of six pounds per square inch. A similar suction pressure is provided in the common suction line.

The coil I1 is fed at its inlet end by the capillary l5 and a second connecting conduit 23 connects provision of a multi-temperature refrigeration the outlet of the pressure difierential valve 22 system having a pair of evaporator coils, a pair to the coil H at a point approximately mid-way of capillary tube supplying refrigerant to these between its inlet and outlet ends. Thus the last 'coils, and a refrigerant return line in heat exportion of the evaporator coil I1 contains both change relation with the capillary tubes. The 40 h refrigerant fed to the @011 IT by the capillary 1 suction line from the common accumulato tubes i5 and also the refrigerant fed through the through which all refrigerant from b t ils coil 19 and pressure differential valve 22 from passes is'in heat exchange relation with the liquid the capillary tube The u l t 01 the low tem- 11 supplying refrigerant t t n t increase perature coil I1 is connected as indicated at 24 the emciency of the system. to an accumulator 25 of suitable design.

These and other objects and novel features of The outlet of the accumulator 25 is connected my invention will be more clearlyand fully set by a common connection 26 to the inlet ll of the forth in the following specification and claims. motor compressor Ill. The suction line 28 ex- In the drawingdorming a part of my speciflcatends in double heat exchange relation with the tion, the drawing diagrammatically illustrates 5o capillary tubes l5 and I6 leading to the two coils.

This feature adds to the economy of the system by tending tc reduce the temperature of the refrigerant as it passes through the capillary tubes is and It.

invention herein lying in the system itself rather My refrigerator system has been found ellident and effective for its intended purpose and produces a well regulated and smooth flow of refrigerant through the system. I have found that both coils can operate to maintain their respective compartments at substantially the desired temperature. Suitable thermostatic con trol, not illustrated in the drawings, is provided to actuate the motor compressor at the necessary times so as to produce the desired temperatures.

In accordance with the patent statutes, I have described the principles of construction and operation of my refrigerating system, and while I have endeavored to set forth the best embodiment thereof. I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A refrigerating system including a refrigerant circulating means, a condensing means for condensing the refrigerant,-a pair of capillary tubes connected to said condenser to receive liquid refrigerant therefrom. a pair of evaporator coils connected to said capillary tubes, the end of one of said coils connected to a mid-point of the other coil, a common return line from the end of said other coil to the refrigerant circulating means, and a pressure differential valve between the end of said one coil and the mid-point of said other coil.

2. The structure described in claim 1 in which the common return line is arranged in heat transfer relation with said capillary tubes.

3. The structure described in claim 1 and including an accumulator in said common return as 2,244,382

eluding an accumulator in said common return I line and in which the common return line is in heat transfer relation with said capillary tubes.

5. A refrigerating system including a refrigerant compressing and circulating means, a condenser for condensing the refrigerant circulated, a pair of capillary tubes connected to said condenser to receive liquid refrigerant therefrom, a coil operating at a relatively high temperature connected to one of said capillary tubes and a coil operating at a relatively low temperature connected to the other of said capillary tubes, a connection between the outlet end of the high temperature coil and a mid-point of the low temperature coil, a pressure differential valve in said connection, and a common return line from the outlet end of said low temperature coil to said compressor and circulating means.

6. The structure described in claim 5 in which the common return line is in heat transfer relation to said capillary tubes.

7. The structure described in claim 5 in which the capillary tubes are varied in length to produce the proper refrigerant flow to each of said coils.

JOHN C. JENKINS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,123,179 Buchanan July 12, 1938 Atchison June 3, 1941 2,262,234 Hoesel Nov. 11. 1941 2,482,171 Gygax Sept. 20, 1949 

